rust-raspberrypi-OS-tutorials/04_mailboxes/src/main.rs
2019-02-03 21:48:55 +01:00

82 lines
2.7 KiB
Rust

/*
* MIT License
*
* Copyright (c) 2018 Andre Richter <andre.o.richter@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#![no_std]
#![no_main]
#![feature(asm)]
const MMIO_BASE: u32 = 0x3F00_0000;
mod gpio;
mod mbox;
mod uart;
use core::sync::atomic::{compiler_fence, Ordering};
fn kernel_entry() -> ! {
let mut mbox = mbox::Mbox::new();
let uart = uart::MiniUart::new();
// set up serial console
uart.init();
uart.puts("\n[0] UART is live!\n");
uart.puts("[1] Press a key to continue booting... ");
uart.getc();
uart.puts("Greetings fellow Rustacean!\n");
// get the board's unique serial number with a mailbox call
mbox.buffer[0] = 8 * 4; // length of the message
mbox.buffer[1] = mbox::REQUEST; // this is a request message
mbox.buffer[2] = mbox::tag::GETSERIAL; // get serial number command
mbox.buffer[3] = 8; // buffer size
mbox.buffer[4] = 8;
mbox.buffer[5] = 0; // clear output buffer
mbox.buffer[6] = 0;
mbox.buffer[7] = mbox::tag::LAST;
// Insert a compiler fence that ensures that all stores to the
// mbox buffer are finished before the GPU is signaled (which is
// done by a store operation as well).
compiler_fence(Ordering::Release);
// send the message to the GPU and receive answer
match mbox.call(mbox::channel::PROP) {
Err(_) => uart.puts("[i] Unable to query serial!\n"),
Ok(()) => {
uart.puts("[i] My serial number is: 0x");
uart.hex(mbox.buffer[6]);
uart.hex(mbox.buffer[5]);
uart.puts("\n");
}
};
// echo everything back
loop {
uart.send(uart.getc());
}
}
raspi3_boot::entry!(kernel_entry);